1. Field of the Invention
The present invention relates to a sample analyzer including a transportation unit for transporting a plurality of sample containers accommodating samples and a measurement unit for measuring the samples accommodated in the sample containers, and a sample transporting method by the sample analyzer.
2. Description of the Related Art
A sample analyzer including a plurality of measurement devices for measuring samples such as blood or urine, and a sample transporting device for distributing a plurality of sample containers to the plurality of measurement devices is conventionally known.
U.S. Patent Publication No. 2009/0227033 discloses a sample analyzer including a first measurement unit, a second measurement unit for measuring samples for other measurement items in addition to measurement items measured by the first measurement unit, and a sample transporting device for transporting a rack accommodating a plurality of sample containers to the first measurement unit and the second measurement unit. In such sample analyzer, when an instruction to start measurement is made by the user, the sample transporting device transports the plurality of sample containers accommodated in the rack, sequentially one by one from the sample container positioned at the head of the rack, to a measurement unit in a state capable of measuring measurement items of the sample in the sample container. The measurement is then carried out sequentially from the sample in the sample container positioned on the head side of the rack.
However, in some racks, a sample (first sample) whose measurement order includes only the measurement item that can be measured in both first and second measurement units and a sample (second sample) whose measurement order includes the measurement item that can be measured only in the second measurement unit coexist. For instance, sample containers from the head to the mth sample container of n sample containers lined in the rack (m is a plural, and n−m≧2) may accommodate the first sample, and (m+1)th to nth sample containers may accommodate the second sample. In such a case, as in the sample transporting device disclosed in U.S. Patent Publication No. 2009/0227033, if the n sample containers accommodated in the rack are transported to the first and second measurement units sequentially from the sample container positioned at the head side of the rack, the sample containers from the head to the mth sample containers are distributed sequentially to the first and second measurement units and measured, and then the (m+1)th to nth sample containers are transported to the second measurement unit sequentially and measured. While the second samples in the (m+1)th to nth sample containers are continuously measured by the second measurement unit, the sample containers are not transported to the first measurement unit. Therefore, in such a case, the first measurement unit cannot be effectively used, and the processing efficiency of the entire sample analyzer may become lower.